Buy Sierra MatchKing Bullets 264 Caliber, 6.5mm (264 Diameter) 142 Grain Hollow Point Boat Tail Online. Sierra MatchKing bullets have very thin jackets and are held to exacting tolerances in diameter and weight. These Hollow Point Boat Tail bullets have a small meplat to produce a higher ballistic coefficient. Their accuracy has been acclaimed worldwide and they have been used to win more target competitions than all target bullets from other manufacturers combined. Buy Sierra MatchKing Bullets 264 Caliber, 6.5mm (264 Diameter) 142 Grain Hollow Point Boat Tail Online. The 6.5mm 142 Grain MatchKing is extremely high performing at long ranges out to 1000 yards. This bullet features a longer ogive radius than the 140 Grain MatchKing resulting in a higher ballistic coefficient. This is not loaded ammunition.